Photoelectric conversion element, method of manufacturing photoelectric conversion element, and electronic device

ABSTRACT

A method of manufacturing a photoelectric conversion element includes: forming a first electrode film such that a first conductive film is connected with a substrate and a second conductive film is connected with the first conductive film; patterning the second conductive film in a predetermined shape using wet etching after the forming of the first electrode film; and forming a metal compound film to cover the first electrode film after the patterning of the second conductive film.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional application of U.S. patent application Ser. No.14/028,940 filed on Sep. 17, 2013. This application claims priority toJapanese Patent Application No. 2012-206654 filed on Sep. 20, 2012. Theentire disclosures of U.S. patent application Ser. No. 14/028,940 andJapanese Patent Application No. 2012-206654 is hereby incorporatedherein by reference.

BACKGROUND

1. Technical Field

The present invention relates to a photoelectric conversion element, amethod of manufacturing a photoelectric conversion element, and anelectronic device.

2. Related Art

So-called CIS thin films which include copper (Cu), indium (In), andselenium (Se) and so-called CIGS thin films which include copper (Cu),indium (In), gallium (Ga), selenium (Se), and the like are known as thinfilms which form semiconductor devices which have a chalcopyritestructure. The CIS and CIGS thin films are frequently used in solarbatteries since the photoelectric conversion rate is excellent. Inaddition, application of the CIS and CIGS thin films to sensors and thelike as photoelectric conversion elements is desired in order to have ahigh light sensitivity over a wide wavelength range from visible lightto near-infrared light.

For example, Japanese Unexamined Patent Application Publication No.2007-123721 (FIG. 2) discloses a photoelectric conversion element whichhas a p type compound semiconductor thin film with a chalcopyritestructure which functions as a light absorbing layer by being laminatedon an electrode film which is provided on a substrate.

SUMMARY

However, in a step where a semiconductor thin film with a chalcopyritestructure is patterned, there is a risk that the electrode film which isthe lower layer may be damaged in a case where a thy etching method isused in order to remove portions of the semiconductor thin film whichare not necessary. In addition, when the etching amount is controlled(suppressed) in order to suppress damage to the electrode film due tothe dry etching, there is a risk that productivity may be decreasedsince residue from the electrode film occurs due to the dry etching andit is necessary to remove the residue using a wet etching method or thelike.

The present invention was carried out in order to solve at least aportion of the problems described above and it is possible to realizethe present invention as the following forms or aspects.

A method of manufacturing a photoelectric conversion element accordingto the present aspect, which is provided with a substrate, a firstelectrode film which has a first conductive film and a second conductivefilm which are provided on the substrate, a metal compound film which isprovided to cover the first electrode film, a semiconductor film whichis provided to be connected with the metal compound film, a secondelectrode film which is provided to be connected with the semiconductorfilm, and an insulating film which is provided to cover and surround thesubstrate, the first electrode film, the semiconductor film, and themetal compound film, is a method which includes forming the firstconductive film to be connected with the substrate and the secondconductive film to be connected with the first electrode film, formingthe second conductive film in a predetermined shape using wet etchingafter the forming of the first conductive film and the second conductivefilm, and forming the metal compound film which covers the firstelectrode film after the forming of the second conductive film.

It is preferable that the method of manufacturing the photoelectricconversion element according to the aspect described above includeforming the semiconductor film to be connected with the metal compoundfilm, forming the metal compound film and the semiconductor film in apredetermined shape, forming the insulating film, and removing a portionof the insulating film and forming the second electrode film to beconnected with the semiconductor film.

According to the method of manufacturing the photoelectric conversionelement, the forming of the first conductive film and the secondconductive film which is formed to connect to the first conductive filmin the predetermined shape using wet etching is performed prior to theforming of the metal compound film. It is possible to apply an etchantwhere the etching rate is slower with regard to the first conductivefilm and faster with regard to the second conductive film in the wetetching which is performed in the forming of the first conductive filmand the second conductive film. Due to this, it is possible toselectively pattern (etch) the second conductive film using wet etchingand it is possible to suppress the etching residue of the secondconductive film which occurs on the first conductive film and tosuppress corrosion of the first conductive film and the substrate.

A photoelectric conversion element according to the present aspect isprovided with a substrate, and a photoelectric conversion section whichhas a first electrode section and a second electrode section which areprovided on the substrate and, and a light absorbing section, where thefirst electrode section has a first conductive film which has a firstsurface and a second surface, which is in a front and back relationshipwith the first surface, and is provided to be connected with thesubstrate and the first surface, and a second conductive film which isconnected with the second surface and provided at the inner side of aperipheral edge of the first conductive film, the light absorbingsection has a metal compound film which covers the second conductivefilm and is provided to be connected with the second surface, asemiconductor film which is provided to be connected with the metalcompound film, and an insulating film which is connected with thesubstrate, surrounds the first conductive film, the metal compound film,and the semiconductor film, and is provided to expose the semiconductorfilm by a portion of the insulating film being opened, and the secondelectrode section has a second electrode film which is provided on theinsulating film to be connected with the semiconductor film which isexposed from the insulating film.

According to the photoelectric conversion element, the second conductivefilm is provided on the second surface of the first conductive film soas to be surrounded by the first conductive film and the metal compoundfilm. Due to this, it is possible to suppress a current which isconverted by the light absorbing section which includes the metalcompound film from leaking out from the second conductive film which isconnected with the metal compound film to the insulating film. Inaddition, it is possible to suppress film peeling of the firstconductive film, the metal compound film, and the insulating film whichoccurs due to the difference in the thermal expansion coefficients (thelinear expansion coefficients) between the first conductive film, andthe metal compound film and the insulating film.

It is preferable that the metal compound film in the photoelectricconversion element according to the aspect described above includecopper (Cu), indium (In), and selenium (Se).

According to the photoelectric conversion element, it is possible toobtain a photoelectric conversion element with high photoelectricconversion efficiency by the metal compound film being a so-called CISthin film with p type characteristics which includes copper, indium, andselenium compared to a case where the metal compound film is a siliconthin film.

It is preferable that the insulating film in the photoelectricconversion element according to the aspect described above includesilicon oxide.

According to the photoelectric conversion element, by including siliconoxide in the insulating film, it is possible to have excellent adhesionbetween the substrate, the first conductive film, the second conductivefilm, the metal compound film, and the semiconductor film which are incontact with the insulating film and to suppress the film peelingbetween each of the films.

An electronic device according to the present aspect is mounted with thephotoelectric conversion element described above.

By applying the photoelectric conversion element described above to theelectronic device, it is possible to realize an improvement in thereliability of the electronic device which is mounted with thephotoelectric conversion element.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIGS. 1A and 1B are diagrams schematically illustrating a schematicconfiguration of a photoelectric conversion element according to a firstembodiment.

FIG. 2 is a flow chart illustrating steps where the photoelectricconversion element according to the first embodiment is manufactured.

FIGS. 3A, 3B, and 3C are diagrams describing steps where thephotoelectric conversion element according to the first embodiment ismanufactured.

FIGS. 4A, 4B and 4C are diagrams describing steps where thephotoelectric conversion element according to the first embodiment ismanufactured.

FIGS. 5A, 5B, and 5C are diagrams describing steps where thephotoelectric conversion element according to the first embodiment ismanufactured.

FIG. 6 is a diagram schematically illustrating a schematic configurationof a photoelectric conversion element according to a second embodiment.

FIG. 7 is a diagram schematically illustrating an electronic deviceaccording to an example.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Below, embodiments of the present invention will be described based onthe diagrams. Here, in each of the diagrams which are illustrated below,since each of the constituent components is set to a size which is ableto be recognized in the diagrams, there are cases in the descriptionwhere the dimensions and proportions of each of the constituentcomponents are appropriately varied from the actual constituentcomponents.

First Embodiment

A photoelectric conversion element and a method of manufacturing aphotoelectric conversion element according to the first embodiment willbe described using FIG. 1 to FIG. 5.

FIGS. 1A and 1B are diagrams illustrating a schematic configuration ofthe photoelectric conversion element according to the presentembodiment. FIG. 2 is a diagram illustrating a flow of steps where thephotoelectric conversion element is manufactured. In addition, FIG. 3 toFIG. 5 are diagrams illustrating steps of manufacturing thephotoelectric conversion element. Here, the photoelectric conversionelement of the present embodiment is, for example, provided in an arrayshape on a substrate as shown in FIG. 1A and the photoelectricconversion elements shown in each of the diagrams are shown as crosssections where a portion is enlarged.

Structure of Photoelectric Conversion Element

A photoelectric conversion element 1 shown in FIG. 1B is provided with asubstrate 110 and a photoelectric conversion section 200. In addition,FIG. 1B illustrates a cross section where the photoelectric conversionelement 1 shown in FIG. 1A is enlarged. Here, the same applies to thephotoelectric conversion element 1 which is illustrated in FIG. 3 toFIG. 5.

The photoelectric conversion section 200 is configured by a firstelectrode section 201, a light absorbing section 202, and a secondelectrode section 203 on the substrate 110 described above.

The first electrode section 201 is provided with a first conductive film210 and a second conductive film 220 which are provided as a firstelectrode film. The light absorbing section 202 is provided with a metalcompound film 230, a semiconductor film 240, and an insulating film 260.In addition, the second electrode section 203 is provided with a secondelectrode film 270.

Here, in the following description, the first electrode film will bedescribed using the same reference numeral (201) as the first electrodesection.

The photoelectric conversion section 200 of the photoelectric conversionelement 1 is provided with a first electrode film 201 on the substrate110 as shown in FIG. 1B and further provided with the light absorbingsection 202 and the second electrode section 203 which overlap with thefirst electrode film 201.

The substrate 110 is formed to include a material such as glass. Forexample, borosilicate glass or the like is used as the substrate 110.

Structure of Photoelectric Conversion Section

The first electrode film 201 is provided with the first conductive film210 on the substrate 110 and the second conductive film 220 on the firstconductive film 210.

The first conductive film 210 has a first surface 210 a and a secondsurface 210 b with a front and back relationship.

The first conductive film 210 is provided with the first surface 210 aconnected with the substrate 110 and is patterned into a predeterminedshape. The first conductive film 210 is provided as a conductive filmwhich includes titanium (Ti) and the like.

The second conductive film 220 is provided to be patterned in apredetermined shape on the first conductive film 210. In more detail,the second conductive film 220 is provided to be connected with thesecond surface 210 b of the first conductive film 210 and is patternedinto the predetermined shape. In addition, the second conductive film220 is provided at the inner side of the peripheral edge in a case wherethe first conductive film 210 is seen in a planar view. In other words,the second conductive film 220 has a region with an area which issmaller than the first conductive film 210 where the second conductivefilm 220 is not provided on the second surface 210 b of the firstconductive film 210.

Here, the second conductive film 220 is provided as a conductive filmwhich includes molybdenum (Mo) and the like.

Next, the light absorbing section 202 is provided with the metalcompound film 230 so as to cover and surround the first electrode film201. In addition, the semiconductor film 240 is provided on the metalcompound film 230. In addition, the insulating film 260 is provided soas to surround the first conductive film 210, the metal compound film230, and the semiconductor film 240 to correspond to the substrate 110.

The light absorbing section 202 of the present embodiment is asemiconductor device which has a chalcopyrite structure and convertslight which is incident on the photoelectric conversion element 1 intoan electric (current) signal.

The light absorbing section 202 is provided with the metal compound film230 as a p type semiconductor which has a chalcopyrite structure whichincludes a Ib (1b) group element, a IIIb (3b) group element, and a VIb(6b) group element, and an n type semiconductor film 240 to be describedlater which is connected with the metal compound film 230.

A metal compound film 231 (230) is provided to include copper (Cu),indium (In), and the like. The metal compound film 231 is provided asthe metal compound film 230, which is selenized, by performing heating,so-called annealing, in a selenium (Se) atmosphere. The selenized metalcompound film 230 described above is a so-called CIS (Cu, In, and Se)thin film.

In addition, it is possible to provide the metal compound film 231 (230)to include copper (Cu), Indium (In), gallium (Ga), and the like. Themetal compound film 231 is provided as the selenized metal compound film230 by performing annealing which is heating in a selenium (Se)atmosphere. The selenized metal compound film 230 described above is aso-called CIGS (Cu, In, Ga, and Se) thin film.

For example, the semiconductor film 240 is provided to include zincoxide (ZnO) and the like in the n type semiconductor film 240.

The insulating film 260 is provided to cover and surround the firstconductive film 210, the metal compound film 230, and the semiconductorfilm 240 to correspond so as to overlap with the substrate 110.

Here, the insulating film 260 is provided with an exposed region 251where a portion is opened and the semiconductor film 240 is exposed. Inother words, the exposed region 251 is a region where the semiconductorfilm 240 is not covered by the insulating film 260. For example, theinsulating film 260 is provided to include silicon oxide (SiO2).

Next, the second electrode section 203 is an electrode film whichextracts the electric (current) signal from the light absorbing section202. The second electrode film 270 is provided to be patterned into apredetermined shape so as to overlap with the insulating film 260. Here,a portion of the second electrode film 270 is connected with thesemiconductor film 240 which is provided in the light absorbing section202 by the exposed region 251. For example, the second electrode film270 is formed as a conductive film which includes ITO (indium tin oxide)and the like.

Method of Manufacturing Photoelectric Conversion Element 1

Next, each step in the manufacturing of the photoelectric conversionelement 1 will be described.

As shown in FIG. 2, the steps in the manufacturing of the photoelectricconversion element 1 include a first electrode film forming step S100, afirst patterning step S200, a metal compound film forming step S300, asemiconductor film forming step S400, a second patterning step S500, aninsulating film forming step S600, and a second electrode film formingstep S700. Below, the steps in the manufacturing of the photoelectricconversion element 1 will be described in order using FIG. 3 to FIG. 5.

First Electrode Film Forming Step

The first electrode film forming step S100 is a step where the firstconductive film 210 and the second conductive film 220 are formed as thefirst electrode film 201.

The first electrode film forming step S100 includes a step where thefirst conductive film 210 which includes titanium (Ti) is formed to beconnected with the substrate 110, a step where the first conductive film210 is patterned in the predetermined shape, and a step where the secondconductive film 220 which includes molybdenum (Mo) is formed to beconnected with the first conductive film 210 which is formed in thepredetermined shape.

FIG. 3A illustrates a state where the first conductive film 210 isformed in the predetermined shape on the substrate 110. In addition,FIG. 3B illustrates a state where the second conductive film 220 isformed on the second surface 210 b of the first conductive film 210described above.

For example, in the step where the first conductive film 210 is formed,a conductive film which includes titanium is formed on the substrate 110using a sputtering method or the like.

For example, in the step where the first conductive film 210 is formedin the predetermined shape, a mask pattern (which is not shown in thediagram) is formed on the second surface 210 b of the first conductivefilm 210 using a photolithography method or the like.

Next, removal (etching) of a portion of the first conductive film 210which is not necessary is performed using a wet etching method or thelike at a region where the mask pattern described above is not formed,that is, the predetermined shape. The removal of the first conductivefilm 210 in the present embodiment uses a wet etching method where thefirst conductive film 210 is immersed in an etchant (an aqueoussolution) which includes hydrofluoric acid, but the etching method isnot limited to this and may be appropriately changed depending on thecomposition or the like of the first conductive film 210 to be removed.

For example, in the step where the second conductive film 220 is formed,a conductive film which includes molybdenum is formed using a sputteringmethod or the like on the first conductive film 210 which is formed inthe predetermined shape.

First Patterning Step

The first patterning step S200 is a step where the second conductivefilm 220 is patterned in the predetermined shape.

FIG. 3C illustrates a state where the second conductive film 220 ispatterned in the predetermined shape in the first patterning step S200.

For example, in the first patterning step S200, a mask pattern (which isnot shown in the diagram) is formed on the second conductive film 220and the substrate 110 using a photolithography method or the like. Next,removal (etching) of a portion of the second conductive film 220 whichis not necessary is performed using a wet etching method or the like ata region where the mask pattern is not formed, that is, thepredetermined shape. In the first patterning step S200 in the presentembodiment, a wet etching method is used where the second conductivefilm 220 is immersed in an etchant (an aqueous solution) which includesnitric acid and phosphoric acid.

It is possible to decrease the etching rate with regard to the firstconductive film 210 and, on the other hand, to increase the etching ratewith regard to the second conductive film 220 by using the etchant whichincludes nitric acid and phosphoric acid. Due to this, it is possible toselectively etch the second conductive film 220 which includesmolybdenum and to suppress corrosion of the first electrode film 201which includes titanium and the substrate 110. In addition, since theetching rate with regard to the second conductive film 220 is fast, itis possible to suppress corrosion, or so-called site etching, of theside surface of the second conductive film 220. Accordingly, it ispossible to suppress residue of the second conductive film 220, which isto be removed in these steps, from occurring on the second surface 2106of the first conductive film 210.

Metal Compound Film Forming Step

The metal compound film forming step S300 is a step where the metalcompound film 230 (231) is formed to be connected with the firstelectrode film 201 and include copper (Cu) and indium (In), or copper(Cu), indium (In), gallium (Ga), and the like.

FIG. 4A illustrates a state where the metal compound film 230 is formedon the first electrode film 201 and the substrate 110 described above inthe metal compound film forming step S300.

For example, in the metal compound film forming step S300, the metalcompound film 231 (230) which includes copper (Cu) and indium (In), orcopper (Cu), indium (In), gallium (Ga), and the like is formed using asputtering method.

In addition, the metal compound film forming step S300 includes aselenization step where heating of the metal compound film 231,so-called annealing, is performed in a selenium (Se) atmosphere. Themetal compound film 231 is formed as a so-called CIS (Cu, In, Se2) thinfilm or a CIGS (Cu, In, Ga, Se2) thin film which is selenized byannealing in a selenium (Se) atmosphere in the selenization step. In theselenization step in the present embodiment, the annealing temperatureis set to approximately 300° C. Here, the annealing temperature may beappropriately changed depending on the composition of the metal compoundfilm 231.

Semiconductor Film Forming Step

The semiconductor film forming step S400 is a step where thesemiconductor film 240 is formed to be connected with the metal compoundfilm 230 which is formed in the metal compound film forming step S300described above.

FIG. 4B illustrates a state where the semiconductor film 240 is formedon the metal compound film 230 in this step.

For example, in the semiconductor film forming step S400, the n typesemiconductor film 240 which includes zinc oxide (ZnO) or the like isformed using a CVD (Chemical Vapor Deposition) method.

Second Patterning Step

The second patterning step S500 is a step where the metal compound film230 and the semiconductor film 240 are formed in a predetermined shape.FIG. 4F illustrates a state where the metal compound film 230 and thesemiconductor film 240 are patterned in the predetermined shape in thesecond patterning step S500.

For example, in the second patterning step S500, a mask pattern (whichis not shown in the diagram) is formed on the semiconductor film 240using a lithography method and removal (etching) of the semiconductorfilm 240 and the metal compound film 230 which are not necessary isperformed by a wet etching method or the like at a region where a maskpattern is not formed, that is, the predetermined shape.

Insulating Film Forming Step

The insulating film forming step S600 is a step where the insulatingfilm 260 is formed so as to surround the first conductive film 210, themetal compound film 230, and the semiconductor film 240 to correspond soas to overlap with the substrate 110.

FIG. 5A illustrates a state where the insulating film 260 is formed inthis step.

For example, in the insulating film forming step S600, the insulatingfilm 260 which includes silicon nitride (SiNx) or silicon oxide (SiO2)is formed using a chemical vapor deposition method. By including siliconoxide in the insulating film 260, the adhesion between the substrate110, the metal compound film 230, the semiconductor film 240, and thesecond electrode film 270 is increased and it is possible to suppressthe peeling between each of these and the insulating film 260.

Second Electrode Film Forming Step

The second electrode film forming step S700 is a step where the secondelectrode film 270 is formed to be connected with the semiconductor film240 described above on the insulating film 260.

The second electrode film forming step S700 includes a step where thesecond electrode film 270 is formed and a step where the exposed region251 which connects the second electrode film 270 and the semiconductorfilm 240 is formed. FIG. 5B illustrates a state where the secondelectrode film 270 is formed to be connected with the semiconductor film240 in this step.

In addition, the second electrode film forming step S700 includes a stepwhere the second electrode film 270 which is formed is patterned in apredetermined shape. FIG. 5C illustrates a state where the secondelectrode film 270 is patterned in the predetermined shape by this step.

In the second electrode film forming step S700, forming of the exposedregion 251 is performed prior to forming of the second electrode film270. For example, in the step where the exposed region 251 is formed, amask pattern (which is not shown in the diagram) where a portion whichis the exposed region 251 is opened is formed on the second electrodefilm 270 using a photolithography method. Next, removal (etching) of theinsulating film 260, which is formed in a portion where the mask patternis opened, that is, a portion which is the exposed region 251, isperformed using a dry etching method or the like. Etching gas whichincludes sulfur hexafluoride (SF6) is used in the dry etching of thepresent embodiment but the dry etching is not limited to this and theetching gas may be appropriately changed according to the compositionand the like of the insulating film 260.

Next, in the second electrode film forming step S700, forming of thesecond electrode film 270 is performed so that the second electrode film270 is connected with the semiconductor film 240. In the forming of thesecond electrode film 270, for example, the second electrode film 270which includes ITO is formed on the insulating film 260 and on thesemiconductor film 240 which is exposed in the exposed region 251 usinga sputtering method.

Next, in the second electrode film forming step S700, a step isperformed where patterning of the second electrode film 270 is performedin the predetermined shape. In the patterning of the second electrodefilm 270, for example, on the second electrode film 270 which is formed,a mask pattern (which is not shown in the diagram) is formed on theinsulating film 260 using a photolithography method and removal(etching) of the second electrode film 270 which is not necessary isperformed using a wet etching method or the like at a region where amask pattern is not formed, that is, the predetermined shape.

In the second electrode film forming step S700 in the presentembodiment, a wet etching method where the second electrode film 270 isimmersed into an etchant (an aqueous solution) which includes oxalicacid is used but the etching method is not limited to this and may beappropriately changed depending on the composition or the like of thesecond electrode film 270 or the like.

When the second electrode film forming step S700 is completed, the stepsin the manufacturing of the photoelectric conversion element 1 arecompleted.

According to the first embodiment described above, the following effectsare obtained.

According to the photoelectric conversion element 1, by performing thefirst patterning step S200 where the second conductive film 220 which isformed on the first conductive film 210 is formed in the predeterminedshape prior to the metal compound film forming step S300 where the metalcompound film 230 is formed, the second conductive film 220 is providedon the first conductive film 210 so as to surround the first conductivefilm 210 and the metal compound film 230.

Due to this, it is possible to selectively remove unnecessary portionsof the second conductive film 220 which is patterned on the firstconductive film 210 using wet etching and it is possible to suppressresidue from the etched second conductive film from occurring +++ on thefirst conductive film 210 and corrosion of the first conductive film 210and the substrate 110.

Accordingly, it is possible to obtain the photoelectric conversionelement 1 with a high SN ratio where current which leaks out from thesecond conductive film 220, that is, dark current, is suppressed.

Second Embodiment

FIG. 6 is a diagram schematically illustrating a schematic configurationof a photoelectric conversion element according to the presentembodiment.

A photoelectric conversion element 2 of the present embodiment is thephotoelectric conversion element 1 which was described in the firstembodiment which is provided with a circuit section 300.

Structure of Photoelectric Conversion Element 2

The photoelectric conversion element 2 shown in FIG. 6 is provided withthe substrate 110, the circuit section 300, and the photoelectricconversion section 200.

The circuit section 300 is provided with a switching element 310 on thesubstrate 110. In addition, the circuit section 300 is provided with aplanarization film 320 which covers the switching element 310.

The photoelectric conversion section 200 is provided with the firstelectrode section 201, the light absorbing section 202, and the secondelectrode section 203 on the planarization film 320 described above.

The photoelectric conversion element 2 is provided on the substrate 110as shown in FIG. 6 to overlap with the circuit section 300 and thephotoelectric conversion section 200.

Structure of Circuit Section

In the circuit section 300, the switching element 310 is provided on thesubstrate 110 as a thin film transistor which is configured by aswitching semiconductor section 311, a source electrode 312, a drainelectrode 313, a gate electrode section 314, a gate insulating section315, an interlayer insulating section 316, and a protective section 317.In the present embodiment, as the switching element 310, a so-calledpolysilicon thin film transistor where polycrystalline silicon is usedin the switching semiconductor section 311 is exemplified. However, theswitching element 310 is not limited to this and an amorphous siliconthin film transistor or a transistor which uses another semiconductorfilm may be provided.

In addition, the planarization film 320 is provided in the circuitsection 300 so as to cover the switching element 310. For example, theplanarization film 320 is provided to include silicon oxide (SiO2).

Structure of Photoelectric Conversion Section

The photoelectric conversion section 200 is provided with the firstelectrode section 201, the light absorbing section 202, and the secondelectrode section 203 overlapping in the same manner as the firstembodiment. In the photoelectric conversion section 200, the firstconductive film 210 and the drain electrode 313 which is provided on thecircuit section 300 are connected. Other than this, since the structureof the photoelectric conversion section 200 is the same as thephotoelectric conversion element 1 which was described in the firstembodiment, description of the structure will be omitted.

Method of Manufacturing Photoelectric Conversion Element 2

Next, the steps of manufacturing the photoelectric conversion element 2will be described.

In the method of manufacturing the photoelectric conversion element 2,the step where the switching element 310 is formed is performed prior tothe step where the photoelectric conversion section 200 of thephotoelectric conversion element 1 which was described in the firstembodiment is manufactured.

In the step where the switching element 310 in the present embodiment isformed, it is possible to use polysilicon thin film transistormanufacturing techniques which are well-known techniques. Here, forexample, in the forming of the planarization film 320 which covers theswitching element 310, it is possible to form a film which includessilicon oxide (SiO2) or the like using the chemical vapor depositionmethod.

Other than this, since the step where the photoelectric conversionelement 2 is manufactured is the same as the step where thephotoelectric conversion element 1 which was described in the firstembodiment is manufactured, description of the step will be omitted.

According to the second embodiment described above, the followingeffects are obtained.

According to the photoelectric conversion element 2, by operating theswitching element 310 according to the electric signal which isconverted by the photoelectric conversion section 200, for example, itis possible to easily detect the portion where light is incident to thephotoelectric conversion element 2 in a case (refer to FIG. 1A) wherethe photoelectric conversion element 2 is provided in an array shape.

Example

Next, based on FIG. 7, an example of the electronic device will bedescribed where the photoelectric conversion element 1 according to oneembodiment of the present invention is applied.

Electronic Device

FIG. 7 is a diagram illustrating an outline of an alcohol concentrationmeasuring apparatus 1000 as an electronic device which is provided withthe photoelectric conversion element 1 according to an embodiment of thepresent invention. The alcohol concentration measuring apparatus 1000shown in FIG. 7 is an apparatus which measures the alcohol concentrationin blood by irradiating light onto the blood which is flowing throughveins and receiving the light which is reflected with the photoelectricconversion element 1.

The alcohol concentration measuring apparatus 1000 is provided with animaging apparatus 1120 which irradiates light onto a finger 1200 andreceives the light which is reflected, and a control apparatus 1140.

The imaging apparatus 1120 is provided with a light emitting section1121 and the photoelectric conversion element 1 as a light receivingsection 1122. In addition, the imaging apparatus 1120 is provided with adetection surface 1160 where the finger 1200 is placed.

The control apparatus 1140 is provided with a light emitting controlsection 1141 which controls the light emitting section 1121, a lightreceiving processing section 1142 which processes the electric signalwhich is output from the photoelectric conversion element 1 as the lightreceiving section 1122, and a measuring section 1143 which measures thealcohol concentration based on the signal which was processed by thelight receiving processing section 1142.

For the alcohol concentration measuring apparatus 1000 as the electronicdevice which is provided with the photoelectric conversion element 1, itis possible to increase the light receiving sensitivity of the lightwhich is reflected from the blood by mounting the photoelectricconversion element 1 according to the embodiments of the presentinvention as the light receiving section 1122.

Here, it is possible for the photoelectric conversion element 1according to an embodiment of the present invention to be applied to,for example, a biometric authentication apparatus, a fingerprint imagingapparatus, a vein pattern imaging apparatus, a solar battery apparatus,and the like in addition to the alcohol concentration measuringapparatus 1000 in FIG. 7.

General Interpretation of Terms

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts. Finally, terms of degree such as“substantially”, “about” and “approximately” as used herein mean areasonable amount of deviation of the modified term such that the endresult is not significantly changed. For example, these terms can beconstrued as including a deviation of at least ±5% of the modified termif this deviation would not negate the meaning of the word it modifies.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. Furthermore, the foregoing descriptions of theembodiments according to the present invention are provided forillustration only, and not for the purpose of limiting the invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A method of manufacturing a photoelectricconversion element, which is provided with a substrate, a firstelectrode film having a first conductive film and a second conductivefilm which are provided on the substrate, a metal compound film coveringthe first electrode film, a semiconductor film connected with the metalcompound film, a second electrode film connected with the semiconductorfilm, and an insulating film covering and surrounding the substrate, thefirst electrode film, the semiconductor film, and the metal compoundfilm, the method comprising: forming the first electrode film such thatthe first conductive film is connected with the substrate and the secondconductive film is connected with the first conductive film; patterningthe second conductive film in a predetermined shape using wet etchingafter the forming of the first electrode film; and forming the metalcompound film to cover the first electrode film after the patterning ofthe second conductive film.
 2. The method of manufacturing thephotoelectric conversion element according to claim 1, furthercomprising, forming the semiconductor film to be connected with themetal compound film; patterning the metal compound film and thesemiconductor film in a predetermined shape; forming the insulatingfilm; removing a portion of the insulating film; and forming the secondelectrode film to be connected with the semiconductor film.
 3. Themethod of manufacturing the photoelectric conversion element accordingto claim 1, wherein the patterning of the second conductive filmincludes patterning the second conductive film so that the secondconductive film is on the first conductive film and in an inner side ofa peripheral edge of the first conductive film.
 4. The method ofmanufacturing the photoelectric conversion element according to claim 3,further comprising: forming the semiconductor film over the metalcompound film; forming the insulating film over the semiconductor film;and opening a portion of the insulating film to expose the semiconductorfilm.
 5. The method of manufacturing the photoelectric conversionelement according to claim 3, wherein the metal compound film includescopper (Cu), indium (In), and selenium (Se).
 6. The method ofmanufacturing the photoelectric conversion element according to claim 3,wherein the insulating film includes silicon oxide.
 7. The method ofmanufacturing the photoelectric conversion element according to claim 1,wherein the patterning of the second conductive film includes patterningthe second conductive film so that a part of the first conductive filmis exposed; and the forming of the metal compound film includes formingthe metal compound film to be connected to the part of the firstconductive film that has been exposed.
 8. The method of manufacturingthe photoelectric conversion element according to claim 2, wherein thepatterning of the metal compound film and the semiconductor filmincludes patterning the metal compound film and the semiconductor filmso that a part of the first conductive film is exposed.
 9. The method ofmanufacturing the photoelectric conversion element according to claim 8,wherein the forming of the insulating film includes covering the part ofthe first conductive film that has been exposed with the insulatingfilm.